222 
PHARMACEUTICAL MEETING. 
everywhere; and they were much respected by the medical profession, 
scientific men, and others,—and why P Because they themselves had a love 
for science, and took a great interest in their business. That was the reason 
they attended so often and were there to-night. He felt that he owed 
much of his success in life to the information he had obtained at the lectures 
and evening meetings, and he would remind his young friends, that if they 
wished to obtain a good position in their profession and in society, they should 
come to the Pharmaceutical Society and get all the information they could, 
and give information also; he believed that this would greatly assist them 
in carrying out the object they had in view. If they must have a hobby, 
let them make their business their hobby, which would pay them better than 
any other, both in position and profit. He therefore would urge them to 
come as often as they could, and to bring an} 7- of their friends connected with 
the business. 
SOLIDIFICATION OP A CONCENTRATED SOLUTION OP 
BOROTARTRATE OP POTASH. 
Mr. Morson described the formation of a solid mass of borotartrate of 
potash, which was laid on the table. He had prepared a concentrated solu¬ 
tion and placed it in a bottle with a view to its being scaled, when it suddenly 
became a solid mass and broke the bottle. The result was before them. A 
similar condition was sometimes observed in citrate of magnesia, which would 
occasionally become hard, like the setting of plaster of Paris. If it were dis¬ 
solved in water, it would go back to its original form. He was unable to say 
whether any heat had been evolved in the present instance, as was often the 
case in these sudden changes. He believed Dr. Redwood, who had examined 
the solidified mass, had some remarks to make upon it. 
Dr. Redwood said that when this subject was first brought under the 
notice of himself and two or three others, it appeared to be a case very ana¬ 
logous to others which had been long known to occur, such, for instance, as 
the turning of transparent and vitreous sugar (barley sugar) into the well- 
known and old pharmaceutical preparation called saccharum penidium, which 
was also sold in the shops under the name of “pulled sugar.” In that case 
the sugar was first converted into the vitreous condition, in which, if it were 
left, it would remain as barley sugar, uncr} 7 stallizable ; the usual process was 
then, at a temperature of about 100°, when it had become a soft solid, to form 
it into a roll, to throw it over a hook fixed to a wall at about the height of 
the operator’s head, to draw it out quickly, then double it up, throw it back 
again over the hook, and repeat this process several times. It was found 
after a little time that instead of the sugar cooling on exposure to the air, it 
became very much hotter, so hot in fact that it was difficult for the operator 
to prevent burning his fingers. Very speedily a change took place, and the 
transparent vitreous mass became perfectly white and opaque, like white 
marble. Chemists had long been in the habit of ascribing that change in the 
sugar to crystallization. It had usually been considered that the sugar passed 
from an amorphous to a crystalline condition. There were other cases of a 
somewhat similar nature ; for instance, they all knew that arsenious acid, in 
the state in which it was obtained by sublimation, and the form in which it 
was generally used in pharmacy, viz. in lumps, consisted of a number of 
strata, differing in degrees of transparency, and some being perfectly opaque. 
When the acid was first formed, it was perfectly vitreous, as transparent as 
glass, but, on being kept for a little time, it became more and more opaque. 
These vitreous and opaque varieties of arsenious acid had attracted a great 
